Aspects of the disclosure relate to computer hardware and software.
To deliver hosted applications, desktops and other resources to users, a provider will often deploy many servers or machines that host and provide the resources to the users. These servers may be divided among one or more server farms or sites. When seeking access to a hosted resource, a user may connect to a server farm or a machine using, for example, a user device, such as a personal computer, laptop or mobile device.
While the machines or server farms are deployed, it may be desirable to perform various maintenance operations. A few examples of when a maintenance operation may be needed include when a database has become corrupt; when one or more of the machines have been selected for upgrade or replacement; when one or more of the machines are to be rebooted; and when a server farm's workload is to be transferred to a different workload. Performing a maintenance operation, however, can cause adverse effects such as a connection or service outage. For example, to perform a maintenance operation a server farm or machine may need to be disconnected or otherwise disabled. Any user attempting to access one of the resources hosted by the affected server farms or machines may, as a result of the connection or service outage, be unable to access the desired hosted resource. Providers may wish to avoid or minimize the impact of a maintenance operation on a user's ability to access a hosted application, desktop or other resource.